Ethylene-based copolymers and their use as flow improvers in mineral oil middle distillates

Abstract

An ethylene-based copolymer which is suitable as a flow improver for mineral oil middle distillates and is composed of a) from 50 to 94% by weight of ethylene; b) from 3 to 30% by weight of one or more vinyl esters of C 2 -C 6 -monocarboxylic acids; c) from 3 to 20% by weight of one or more aminoalkyl acrylates of the formula I ##STR1## which R 1 is hydrogen or methyl, R 2 and R 3 are identical or different and are each hydrogen or C 1 -C 6 -alkyl and A 1 is straight-chain or branched C 2 -C 10 -alkylene; and d) from 0 to 10% by weight of one or more monomers which are copolymerizable with the monomers a) to c), wherein copolymers containing vinyl acetate as monomer b) and having a number average molecular weight of from 5,000 to 50,000 are excluded from the scope of the copolymer.

We claim: 
     
       1. A process for improving the flow properties of a mineral oil middle distillate, which comprises adding an ethylene based copolymer which is comprised of: a) from 50 to 94% by weight of ethylene;   b) from 3 to 30% by weight of one or more vinyl esters of C 2  -C 6  -monocarboxylic acids;   c) from 3 to 20% by weight of one or more aminoalkyl acrylates of the formula I ##STR4## which R 1  is hydrogen or methyl, R 2  and R 3  are identical or different and are each hydrogen or C 1  -C 6  -alkyl and A 1  is straight-chain or branched C 2  -C 10  -alkylene; and   d) from 0 to 10% by weight of one or more monomers which are copolymerizable with the monomers a) to c), to the mineral oil middle distillate, wherein copolymers containing vinyl acetate as monomer b) and having a number average molecular weight of from 5,000 to 50,000 are excluded from the scope of the copolymer.   
     
     
       2. A process as claimed in claim 1, wherein a copolymer having a weight average molecular weight of from 500 to 5000 is added to a mineral oil middle distillate. 
     
     
       3. A mineral oil middle distillate containing a flow-improving effective amount of an ethylene based copolymer which is comprised of: a) from 50 to 94% by weight of ethylene;   b) from 3 to 30% by weight of one or more vinyl esters of C 2  -C 6  -monocarboxylic acids;   c) from 3 to 20% by weight of one or more aminoalkyl acrylates of the formula I ##STR5## which R 1  is hydrogen or methyl, R 2  and R 3  are identical or different and are each hydrogen or C 1  -C 6  -alkyl and A 1  is straight-chain or branched C 2  -C 10  -alkylene; and   d) from 0 to 10% by weight of one or more monomers which are copolymerizable with the monomers a) to c), wherein copolymers containing vinyl acetate as monomer b) and having a number average molecular weight of from 5,000 to 50,000 are excluded from the scope of the copolymer.